Veteran’s Memorial Lake: Fish Community & Blue-Green Algae, In-Lake Restoration Bryan Sowards Fish Biologist KDWPT

Veteran’s Lake 13 acres 7.3’ ave. depth 99 acre feet

FISHERY HISTORY 1987 – Rotenone to reset fishery 1990s – Developed Bluegill, Largemouth Bass, Channel Catfish community. Began Rainbow Trout fishery (1997). 2000s – Crappie, Common Carp, Gizzard Shad showed back up. Stocked Saugeye as additional predator.

FISHERY OVERVIEW Good populations of Bluegill, Largemouth Bass, and Saugeye. Largemouth Bass have been strong with 50% or more of the population larger than 12”. Saugeye reached sizes greater than 21” regularly. Rough fish have been a problem but not more than other regional lakes and ponds.

FISHERY OVERVIEW October 2015 sample indicated no Saugeye or any top predators. There is probably LMB but haven’t sampled for them yet. Forage species, Bluegill, Gizzard Shad, Green Sunfish fairly abundant but not overwhelmingly. Few Common Carp. Channel Catfish were naturally reproducing.

FISHERY OVERVIEW Catfish & Trout Program: Since 1987 SPECIES# STOCKED2015 APP. VALUUE Channel Catfish26,599Difficult to determine Hatchery & Commercial ≈$8,100 ($1.00/lb.) Rainbow Trout77,012 fish 45,000 lbs. $175,500 ($3.90/lb.) APP. TOTAL INVESTMENT$183,600

BLUE-GREEN ALGAE 2010 – Blue-Green Algae External Source: Geese, urban runoff, etc. Internal Source: Internal P loading/cycling Benthic fish disturbance? 2011 – Last stocking of Rainbow trout ***stockings moved to Stone Lake. Very little fish management has occurred since 2011.

What has this meant to the fishery? Fish Kills: 2011 and August of Summertime, classic eutrophication-based die offs. Not complete kills but significant.

What has this meant to the fishery? Catfish & Trout: Popular put-and-take fishery since 1990s. Stockings cease due to HAB…fish kill risk. Constant complaints that people had trouble catching trout at Stone Lake. They wanted fish back in Veteran’s Lake.

What has this meant to the fishery? Trout Permit Sales – Barton Co. YearPermit Sales ($$) 2007$2, $2, $2, TOTAL (2007 – 2009)$7, $1, $ $1, TOTAL (2011 – 2013)$3, BG Algae 2010

Restoration Contractor Recommendations: 1.Public Education 2.Reduce external P loading – Stormwater plans, goose removal 3.Monitor 4.Internal P loading (ALUM) 5.Restocking, ecosystem balance

Restoration 2015 Veteran’s Lake Geese Deterrent Details: *Scott… Propane Cannons (negative public opinion) Screamers***(effective; multi-day use)

Restoration 2015 Veteran’s Lake Alum Treatment Details: *Contractor sampled TP in water column & sediment. *Liquid Alum was used. *They used a dose of 10:1 (Al:TP) for both media. Dose was based on active ingredient & not total Alum mass. *Total dose for both media recommended was 5,200 gal. of liquid alum & equates to 2,500 lbs. active ingredient. *They rounded up to 16, 330-gal. totes (5,280 gal.).

Restoration 2015 Veteran’s Lake Alum Treatment Details: Goal for TP is 60 – 100 µg/L after dosing. Within this concentration range the contractor recommends ceasing Alum treatments.

Restoration Concerns The plan did not mention buffering pH which fell from app. 8.5 to 6.8 after treatment. Fell to 6.2 after 2 nd treatment. Plan includes multiple Alum treatments (2 already). The application rate was fixed (10:1) and not adjusted for sediment mobile P fractions (?). Application rate ended up being app g/m 2 ; recent publications suggest 100 g/m 2 but worldwide mean is app. 31 ± 24 g/m 2.

Progress There has been a definite improvement in water clarity. TP fell from 250 µg/L (9/2014) to 220 µg/L prior to treatment. After treatment the TP has fallen to 70 µg/L (7/2015). Monitoring will continue. Fish management has resumed at the lake. Trout have been restocked. More predators will be stocked and Common Carp will continue to be thinned out.

Progress

TP - May

TP - August TP goals reached during Summer 2015!

DO

pH After both treatments there was a marked decrease in pH. The late June pH was nearly 6.2 (concerning)

Turbidity Sechi depth is improving. As of August it was nearly 2.1 ft. and dropping. The picture shows jar test in October, 2015.

Future Continue to monitor water quality parameters & fish populations. TP & cell counts over time. The past summer was promising! This summer will be critical. Limit Biomass Keep geese off pond. Common Carp removal.

Future Common Carp removal: Some studies have shown massive carp removals in lakes with high TP levels to be successful at controlling HAB. -Increases sechi depths -Can decrease water column TP -Moves lake from turbid/algal state to clear/macrophyte state***

Lake Wingra, Wisconsin 2007, turbid/algal state (high densities of Carp) 2012, clear/macrophyte state (low densities of Carp)

Common Carp Exclusion…

Application While this project is ongoing there are many cases in which Alum treatments, done with due diligence and planning, can be very effective. Internal P cycling can account for over 90% of total summer P load. Water quality goals have been shown to last for 4 – 10 yrs. Or more. Emphasizes the need for more In-Lake Management such as Alum treatments.

QUESTIONS?